Senior System Administrator – TS/SCI with Poly (On-Call)

Cornerstone Defense LLC; Herndon (VA); On-site; USD 85,000 - 125,000; Full time

Benefits offered by this job

401(K) with company match

Tuition and training assistance

Job summary

Cornerstone Defense is seeking a System Administrator in Herndon, VA with Active TS/SCI with Polygraph to support a small group of end users and multiple systems. The role requires strong system administration skills across Linux/Unix and Windows platforms, excellent communication with customers, and flexibility to work day, night, weekend, and holiday shifts.

The position emphasizes maintaining documentation, monitoring performance, and contributing to performance optimizations.

Qualifications

• 5+ years of related work experience.
• Experience in System Administration (Linux/Unix or Windows platforms).
• Experience in communicating with customer representatives regarding technical subjects.
• Willingness to complete on-the-job training (OJT).
• Willingness and ability to work variable shifts, including days, nights, weekends, and holidays.

Responsibilities

• Support a small group of end users who use our system and several other systems we support.
• Monitor system performance and troubleshoot issues, sometimes under time pressure.
• Analyze system performance, identify bottlenecks, and document proposed optimizations to improve efficiency.
• Maintain accurate documentation of system configurations, procedures, and troubleshooting steps.
• Interface with customers and represent the System Admin Team during high impact operations.

Skills

5+ years experience

System Administration

Linux/Unix

Windows

Customer communication

OJT training

Shift work

Tools

Active Directory

Group Policy

DNS

DHCP

VDI

VMware ESXi

Job description

Cornerstone Defense is seeking a System Administrator in Herndon, VA with Active TS/SCI with Polygraph to support a small group of end users and multiple systems. The role requires strong system administration skills across Linux/Unix and Windows platforms, excellent communication with customers, and flexibility to work day, night, weekend, and holiday shifts.

The position emphasizes maintaining documentation, monitoring performance, and contributing to performance optimizations.